Boss weapons are unique pieces of equipment across the Dark Souls series, but they are arguably the most tedious to obtain in the original game (and by extension its remastered port).
However, there are a great many benefits to acquiring these weapons, from the immense damage potential they have to securing different trophies/achievements for being diligent with collecting them all, so if you want to explore all the content the game has to offer, you should definitely consider investing the time and resources into procuring them.
In this article, we will go over all the steps necessary to take a standard weapon and morph it into a powerful tool of destruction.
Gather Boss Souls

As the name implies, defeating bosses is the most crucial step to put you on the path towards crafting a these special weapons. Most unique bosses you defeat will drop their soul upon their demise, which is the primary ingredient for forging.
Please be aware that you may be able to create multiple different weapons with a particular boss soul, depending on which it is, and thus getting all the weapons will require defeating the same boss multiple times, and by extension, require more runs through the game (you need to fully complete the game a minimum of three times to have all the resources to craft all available boss weapons).
Find the Blacksmith
The next step to putting together these weapons is to locate the Giant Blacksmith NPC. This character is the only smith in the game that can “ascend” weapons with boss souls.
Unfortunately, he is located all the way in Anor Londo, which is about halfway through the main game. His room can be found by following the left side of the upper floors of the main cathedral hall in Anor Londo – the massive chamber before the boss fight with Dragonslayer Ornstein and Executioner Smough.
He sells a variety of titanite stones, which, provided you have a generous amount of souls to purchase them, can be helpful in completing the third step.
Upgrade Your Weapons

If you’re familiar with smithing mechanics in Dark Souls, you are aware that you need to have a weapon you want to ascend, whether it be to enchanted, elemental or boss status.
In order for a weapon to be eligible to be ascended with a boss soul, it must be upgraded to +10, which requires several regular and large titanite shards, and a trip to Andre the blacksmith in the Undead Parish to ascend the selected weapon past +5.
It’s important to note that the type of weapon is contingent on what you want to get out of the boss’s soul. So, for example, if you take the Soul of Smough and want to craft his great hammer, you will need to ascend any blunt type weapon (mace, hammer, etc) to +10 – you can’t use a sword, ax, or any other type of weapon – they have to broadly match with what you’re crafting.
In other words, if the boss weapon you want to create is a great sword type weapon, upgrade any standard great sword to +10; if it’s a great ax, do the same.
There is one big exception to needing to upgrade a weapon to +10 before it can be ascended to boss status. Tools that cannot be upgraded by default, such as staffs or talismans, need only be presented with the corresponding boss soul to create the weapon. If you’re going for the Knight’s Honor achievement/trophy, obtaining these unique weapons are a walk in the park and should be saved for last.
Remember that even after creating a boss weapon, you’ll still want to upgrade it further (to a maximum of +5) to get the most out of it. They can only be strengthened with demon titanite, which is typically dropped by titanite demons, so if you want to upgrade all the boss weapons, be sure to take out every one of these enemies you see!